Bioinspired catecholamine-derived AuNPs@polynorepinephrine@MWCNT electroactive nanomaterial for real-time monitoring of glucose dynamics

A bioinspired nanomaterial is introduced based on polynorepinephrine (PNE) grafted to multi-walled carbon nanotubes (MWCNT) with gold nanoparticle decoration (Au NPs), developed as an advanced electroactive interface for glucose biosensing. The nanoplatform was deposited on a screen-printed electrode (SPE) with glucose oxidase (GOx) from Aspergillus niger for potential use in point-of-care testing based on a rapid electrocatalytic response to glucose. This molecular-level modification strategy provides an effective approach to tailor catecholamine-derived polymers and improve their electrochemical performance. This biosensor demonstrated a wide linear range (0.1-30.0 mM), with a limit of detection of 2.15 µM and a limit of quantification of 6.52 µM, and sustained stability up to 20 weeks. The biosensor was used to perform in vitro tests with other analytical devices, including a clinical glucometer and a home glucometer. The repeatability and reproducibility of the biosensor were also tested, as well as the possibility of collection of data on changing levels of blood glucose throughout the day. The results demonstrate that the proposed polynorepinephrine-based biosensor represents a promising alternative electroactive coating to the widely studied polydopamine. From an engineering standpoint, the synthesis is compatible with fabrication of screen-printed electrodes. This platform underscores its suitability for potential decentralized point-of-care testing.